os.__file__ not always set #1943
Description
Environment data
- debugpy version: 1.8.16
- OS and version: Windows 11
- Python version: 3.13
- Using VS Code or Visual Studio: VSCode
- briefcase version: 0.3.24
Actual behavior
I am trying to run
import debugpy
debugpy.listen(5678)
in an application that is bundled with briefcase but I get the following error message:
Traceback (most recent call last):
File "asyncio\events.py", line 89, in _run
File "...\build\helloworld\windows\app\src\app_packages\toga\app.py", line 655, in _startup
self.startup()
~~~~~~~~~~~~^^
File "...\build\helloworld\windows\app\src\app\helloworld\app.py", line 218, in startup
debugpy.listen(5678)
~~~~~~~~~~~~~~^^^^^^
File "...\build\helloworld\windows\app\src\app_packages\debugpy\public_api.py", line 44, in wrapper
from debugpy.server import api
File "...\build\helloworld\windows\app\src\app_packages\debugpy\server\__init__.py", line 7, in <module>
import debugpy._vendored.force_pydevd # noqa
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "...\build\helloworld\windows\app\src\app_packages\debugpy\_vendored\force_pydevd.py", line 44, in <module>
preimport('pydevd', [
~~~~~~~~~^^^^^^^^^^^^
'_pydev_bundle',
^^^^^^^^^^^^^^^^
...<5 lines>...
'pydevd',
^^^^^^^^^
])
^^
File "...\build\helloworld\windows\app\src\app_packages\debugpy\_vendored\__init__.py", line 126, in preimport
import_module(name)
~~~~~~~~~~~~~^^^^^^
File "importlib\__init__.py", line 88, in import_module
File "...\build\helloworld\windows\app\src\app_packages\debugpy\_vendored\pydevd\pydevd.py", line 39, in <module>
import pydevd_file_utils
File "...\build\helloworld\windows\app\src\app_packages\debugpy\_vendored\pydevd\pydevd_file_utils.py", line 98, in <module>
_library_dir = _get_library_dir()
File "...\build\helloworld\windows\app\src\app_packages\debugpy\_vendored\pydevd\pydevd_file_utils.py", line 91, in _get_library_dir
library_dir = os.path.dirname(os.__file__)
^^^^^^^^^^^
AttributeError: module 'os' has no attribute '__file__'. Did you mean: '__all__'?
Expected behavior
No error should be thrown.
Steps to reproduce:
- Follow the beeware tutorial to create an windows application
- Add
requires = ["debugpy"]topyproject.toml - Add
import debugpy
debugpy.listen(5678)
- Start application with
briefcase run -r -u
Investigations
Since Python 3.11 there are frozen imports for speedup eg. for os. With frozen import the bytecode is statically allocated by the interpreter, so that it is hard to tell the correct location of os.py for the interpreter. There has been an PR python/cpython#28656 that tries setting os.__file__ even with frozen imports, but it fails in some situations.
In my case that error is occuring, because briefcase is using an embedded isolated python instance (initialized with PyConfig_InitIsolatedConfig()) and does not set PyConfig.stdlib_dir explicitly. See here in the briefcase template This results in a configuration, that os.__file__ is not set. If I add modify the template, so that PyConfig.stdlib_dir is set to some location and then os.__file__ is also set. But this is not the right bugfix, because I have no vaild path for PyConfig.stdlib_dir.
As a consequence, one must assume that os.__file__ is not always available and use hasattr(os, '__file__') to check if it is available.